I have a wife. I love my wife. My wife loves me. I cannot return my wife’s love for me at the same amount or manner. She loves me more than I can ever love her. She loves me in ways I can never.

It’s very poetically written and sounds very loving. My simple translation loses a lot of beauty.

Poetic way of saying that he is really thankful for her and is indebted to her (not in a literal monetary sense, just that her support and love is without bound, such that his own can never measure up against it).

That it's not possible for him to love her back as much as she does. "Requite" is quite an obscure word, I've only ever seen it used in the phrase "unrequited love", which means a love which isn't returned (in quite a different sense than what is used here, since I assume that the author didn't mean that he didn't love his wife, only that his love didn't measure up).

My interpretation would be that he feels his wife is incredibly loving in a quantity he isn’t able to match (degree) and in a unique way he’s not able to match (kind). General life experience plus the fact that he wrote that tells me he’s probably wrong and his wife would probably say the same about him, but that’s just speculation.